Google confirmed Wednesday that it is experimenting with banner advertisements above search results, breaking a promise the company made in 2005 never to do so.

Several advertisers are testing banner ads with Google, including Southwest Airlines, which was first spotted by the web app Synrgy. Google confirmed the testing as part of a larger experiment running banner ads on desktop computers. For example, the Southwest Airlines ad resembles more of a search result than Google’s typical ad units, taking up a large portion of the site real estate.

In 2005, then-vice president Marissa Mayer vowed never to run banner ads in search. “There will be no banner ads on the Google homepage or Web search results pages. There will not be crazy, flashy, graphical doodads flying and popping up all over the Google site. Ever,” she wrote in a blog post.

The experiment comes at a time when Google is dealing with a stagnant desktop search business which has resulted in falling ad prices, the New York Timesreports.